Selection of Water Transmission Method and Analysis of Pipe Network Zoning in Municipal Water Supply and Drainage Design

With the acceleration of urbanization,the demand for water supply and drainage pipe networks has increased significantly.In the planning of urban construction,it is necessary to optimize the design of the water supply and drainage system pipe network to effectively save energy while providing residents with more accessible water resources.Therefore,the municipal water supply and drainage system and the water transmission methods should be designed according to the geographical conditions of the city.In this paper,we mainly analyze the design of municipal water supply and drainage systems and the selection of water transmission methods.Besides,the optimization of the water supply and drainage network zoning process and pipe network maintenance is also discussed,so as to provide a reference for municipal water supply and drainage work.

A comparison study on structure-function relationship of polysaccharides obtained from sea buckthorn berries using different methods:antioxidant and bile acid-binding capacity

In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.

Use of endoscopic ultrasound-guided gallbladder drainage as a rescue approach in cases of unsuccessful biliary drainage

This narrative review provides an overview of the utilization of endoscopic ultrasound-guided gallbladder drainage(EUS-GBD)as a salvage approach in cases of unsuccessful conventional management.EUS-GBD is a minimally invasive and effective technique for drainage in patients with acute cholecystitis with high risk of surgery.The procedure has demonstrated impressive technical and clinical success rates with low rates of adverse events,making it a safe and effective option for appropriate candidates.Furthermore,EUS-GBD can also serve as a rescue option for patients who have failed endoscopic retrograde cholangiopancreatography or EUS biliary drainage for relief of jaundice in malignant biliary stricture.However,patient selection is critical for the success of EUS-GBD,and proper patient selection and risk assessment are important to ensure the safety and efficacy of the procedure.As the field continues to evolve and mature,ongoing research will further refine our understanding of the benefits and limitations of EUS-GBD,ultimately leading to improved outcomes for patients.

Hybrid Strategy of Partitioned and Monolithic Methods for Solving Strongly Coupled Analysis of Inverse and Direct Piezoelectric and Circuit Coupling

The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy harvesters.Existing strongly coupled analysis methods based on direct numerical modeling for this phenomenon can be classified into partitioned or monolithic formulations.Each formulation has its advantages and disadvantages,and the choice depends on the characteristics of each coupled problem.This study proposes a new option:a coupled analysis strategy that combines the best features of the existing formulations,namely,the hybrid partitioned-monolithic method.The analysis of inverse piezoelectricity and the monolithic analysis of direct piezoelectric and circuit interaction are strongly coupled using a partitioned iterative hierarchical algorithm.In a typical benchmark problem of a piezoelectric energy harvester,this research compares the results from the proposed method to those from the conventional strongly coupled partitioned iterative method,discussing the accuracy,stability,and computational cost.The proposed hybrid concept is effective for coupled multi-physics problems,including various coupling conditions.

Endoscopic ultrasound-guided biliary drainage using electrocauteryenhanced lumen-apposing metal stent for malignant biliary obstruction:A promising procedure

In this editorial,we comment on the article by Peng et al.Palliative drainage for biliary obstruction resulting from unresectable malignant lesions includes internal and external drainage.The procedures of biliary drainage are usually guided by fluoroscopy or transcutaneous ultrasound,endoscopic ultrasound(EUS),or both.Endoscopic retrograde cholangiopancreatography(ERCP)has been primarily recommended for the management of biliary obstruction,while EUS-guided biliary drainage and percutaneous transhepatic biliary drainage(PTBD)are alternative choices for cases where ERCP has failed or is impossible.PTBD is limited by shortcomings of a higher rate of adverse events,more reinterventions,and severe complications.EUS-guided biliary drainage has a lower rate of adverse events than PTBD.EUS-guided biliary drainage with electrocautery-enhanced lumen-apposing metal stent(ECE-LAMS)enables EUS-guided biliaryenteric anastomosis to be performed in a single step and does not require prior bile duct puncture or a guidewire.The present meta-analysis showed that ECELAMS has a high efficacy and safety in relieving biliary obstruction in general,although the results of LAMS depending on the site of biliary obstruction.This study has highlighted the latest advances with a larger sample-based comprehensive analysis.

Endoscopic ultrasound-guided biliary drainage vs percutaneous transhepatic bile duct drainage in the management of malignant obstructive jaundice

BACKGROUND Malignant obstructive jaundice(MOJ)is a condition characterized by varying degrees of bile duct stenosis and obstruction,accompanied by the progressive development of malignant tumors,leading to high morbidity and mortality rates.Currently,the two most commonly employed methods for its management are percutaneous transhepatic bile duct drainage(PTBD)and endoscopic ultrasound-guided biliary drainage(EUS-BD).While both methods have demonstrated favorable outcomes,additional research needs to be performed to determine their relative efficacy.To compare the therapeutic effectiveness of EUS-BD and PTBD in treating MOJ.METHODS This retrospective analysis,conducted between September 2015 and April 2023 at The Third Affiliated Hospital of Soochow University(The First People’s Hospital of Changzhou),involved 68 patients with MOJ.The patients were divided into two groups on the basis of surgical procedure received:EUS-BD subgroup(n=33)and PTBD subgroup(n=35).Variables such as general data,preoperative and postoperative indices,blood routine,liver function indices,myocardial function indices,operative success rate,clinical effectiveness,and complication rate were analyzed and compared between the subgroups.RESULTS In the EUS-BD subgroup,hospital stay duration,bile drainage volume,effective catheter time,and clinical effect-iveness rate were superior to those in the PTBD subgroup,although the differences were not statistically significant(P>0.05).The puncture time for the EUS-BD subgroup was shorter than that for the PTBD subgroup(P<0.05).Postoperative blood routine,liver function index,and myocardial function index in the EUS-BD subgroup were significantly lower than those in the PTBD subgroup(P<0.05).Additionally,the complication rate in the EUS-BD subgroup was lower than in the PTBD subgroup(P<0.05).CONCLUSION EUS-BD may reduce the number of punctures,improve liver and myocardial functions,alleviate traumatic stress,and decrease complication rates in MOJ treatment.

Stability Analysis and Performance Evaluation of Additive Mixed-Precision Runge-Kutta Methods

Additive Runge-Kutta methods designed for preserving highly accurate solutions in mixed-precision computation were previously proposed and analyzed.These specially designed methods use reduced precision for the implicit computations and full precision for the explicit computations.In this work,we analyze the stability properties of these methods and their sensitivity to the low-precision rounding errors,and demonstrate their performance in terms of accuracy and efficiency.We develop codes in FORTRAN and Julia to solve nonlinear systems of ODEs and PDEs using the mixed-precision additive Runge-Kutta(MP-ARK)methods.The convergence,accuracy,and runtime of these methods are explored.We show that for a given level of accuracy,suitably chosen MP-ARK methods may provide significant reductions in runtime.

A Review on Sources,Extractions and Analysis Methods of a Sustainable Biomaterial:Tannins

Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses.

High-Order Decoupled and Bound Preserving Local Discontinuous Galerkin Methods for a Class of Chemotaxis Models

In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-dependent problems.We use the convex splitting method,the variant energy quadratization method,and the scalar auxiliary variable method coupled with the LDG method to construct first-order temporal accurate schemes based on the gradient flow structure of the models.These semi-implicit schemes are decoupled,energy stable,and can be extended to high accuracy schemes using the semi-implicit spectral deferred correction method.Many bound preserving DG discretizations are only worked on explicit time integration methods and are difficult to get high-order accuracy.To overcome these difficulties,we use the Lagrange multipliers to enforce the implicit or semi-implicit LDG schemes to satisfy the bound constraints at each time step.This bound preserving limiter results in the Karush-Kuhn-Tucker condition,which can be solved by an efficient active set semi-smooth Newton method.Various numerical experiments illustrate the high-order accuracy and the effect of bound preserving.

Red cell distribution width-to-albumin ratio is a simple promising prognostic marker in acute cholangitis requiring biliary drainage

Background: It is crucial to assess the severity of acute cholangitis(AC). There are currently several prognostic markers. However, the accuracies of these markers are not satisfied. The present study aimed to investigate the predictive value of the red cell distribution width(RDW)-to-albumin ratio(RAR) for the prognosis of AC. Methods: We retrospectively evaluated consecutive patients diagnosed with AC between May 2019 and March 2022. RAR was calculated, and its predictive ability for in-hospital mortality, intensive care unit(ICU) admission, bacteremia, and the length of hospitalization were analyzed. Results: Out of 438 patients, 34(7.8%) died. Multivariate analysis showed that malignant etiology [odds ratio(OR) = 4.816, 95% confidence interval(CI): 1.936-11.980], creatinine(OR = 1.649, 95% CI: 1.095-2.484), and RAR(OR = 2.064, 95% CI: 1.494-2.851) were independent risk factors for mortality. When adjusted for relevant covariates, including age, sex, malignant etiology, Tokyo severity grading(TSG), Charlson comorbidity index, and creatinine, RAR significantly predicted mortality(adjusted OR = 1.833, 95% CI: 1.280-2.624). When the cut-off of RAR was set to 3.8, its sensitivity and specificity for mortality were 94.1% and 56.7%, respectively. Patients with an RAR of > 3.8 had a 20.9-fold(OR = 20.9, 95% CI: 4.9-88.6) greater risk of mortality than the remaining patients. The area under the curve value of RAR for mortality was 0.835(95% CI: 0.770-0.901), which was significantly higher than that of TSG and the other prognostic markers, such as C-reactive protein-to-albumin ratio, and procalcitonin-to-albumin ratio. Lastly, RAR was not inferior to TSG in predicting ICU admission, bacteremia, and the length of hospitalization. Conclusions: RAR successfully predicted the in-hospital mortality, ICU admission, bacteremia, and the length of hospitalization of patients with AC, especially in-hospital mortality. RAR is a promising marker that is more convenient than TSG and other prognostic markers for predicting the prognosis of patients with AC.

Review of Collocation Methods and Applications in Solving Science and Engineering Problems

The collocation method is a widely used numerical method for science and engineering problems governed by partial differential equations.This paper provides a comprehensive review of collocation methods and their applications,focused on elasticity,heat conduction,electromagnetic field analysis,and fluid dynamics.The merits of the collocation method can be attributed to the need for element mesh,simple implementation,high computational efficiency,and ease in handling irregular domain problems since the collocation method is a type of node-based numerical method.Beginning with the fundamental principles of the collocation method,the discretization process in the continuous domain is elucidated,and how the collocation method approximation solutions for solving differential equations are explained.Delving into the historical development of the collocation methods,their earliest applications and key milestones are traced,thereby demonstrating their evolution within the realm of numerical computation.The mathematical foundations of collocation methods,encompassing the selection of interpolation functions,definition of weighting functions,and derivation of integration rules,are examined in detail,emphasizing their significance in comprehending the method’s effectiveness and stability.At last,the practical application of the collocation methods in engineering contexts is emphasized,including heat conduction simulations,electromagnetic coupled field analysis,and fluid dynamics simulations.These specific case studies can underscore collocation method’s broad applicability and effectiveness in addressing complex engineering challenges.In conclusion,this paper puts forward the future development trend of the collocation method through rigorous analysis and discussion,thereby facilitating further advancements in research and practical applications within these fields.

Glaucoma drainage device implantation and cyclophotocoagulation in the management of refractory glaucoma after Descemet-stripping automated endothelial keratoplasty

AIM:To compare the surgical outcomes of glaucoma drainage device implantation(GDI)and trans-scleral neodymium:YAG cyclophotocoagulation(CPC)in the management of refractory glaucoma after Descemetstripping automated endothelial keratoplasty(DSAEK).METHODS:This retrospective study on observational case series enrolled 29 patients who underwent DSAEK and posterior anti-glaucoma surgery(15 with GDI and 14 with CPC).The main outcome measures were intraocular pressure(IOP),glaucoma surgery success rate(defined as IOP of 6–21 mm Hg without additional anti-glaucoma operation),number of glaucoma medications,endothelial graft status,and best-corrected visual acuity(BCVA).RESULTS:The mean follow-up time was 34.1 and 21.0mo for DSAEK or glaucoma surgeries,both for the GDI and CPC groups.Both groups showed significant IOP reduction after glaucoma surgery.The GDI group presented a significantly higher success rate in IOP control than the CPC group(60%vs 21.4%,P=0.03).Both procedures significantly decreased the number of glaucoma medications(P=0.03).Forty percent and 57%of cases in the GDI and the CPC group,respectively,experienced endothelial graft failure during follow-up(P=0.36).Significantly worse BCVA after surgery was observed in the CPC group but not in the GDI group.CONCLUSION:Both GDI and CPC significantly decrease IOP in eyes with glaucoma after DSAEK.GDI is preferable to CPC in refractory glaucoma cases after DSAEK,as it manifests a significantly higher success rate for IOP control,similar endothelial graft failure rate,and relatively preserves BCVA than CPC.

Efficacy and safety analysis of continued nursing of complications in discharged patients after percutaneous transhepatic biliary drainage

BACKGROUND Percutaneous hepatobiliary drainage(PTCD)is an effective method for the treatment of biliary obstruction and other diseases,but postoperative complications are still one of the important problems faced by patients.Continuous nursing is a comprehensive nursing model that plays an important role in postoperative recovery.The purpose of this study was to investigate the effect of continuous nursing on the incidence of complications in patients after PTCD surgery through meta-analysis and to evaluate its efficacy and safety.AIM To evaluate the effect of extended nursing on the incidence of complications in discharged patients after percutaneous transhepatic biliary drainage(PTBD).METHODS Randomized controlled studies on PTBD postdischarge extended care were identified in the CNKI,Wanfang,VIP,CBM,PubMed,Cochrane Library,Embase,Web of Science,and other databases.The quality of the included studies was evaluated using the Joanna Briggs Institute of Australia literature quality evaluation tool,and a meta-analysis of the included studies was performed with RevMan 5.4 software.RESULTS Finally,9 studies were included,with a total sample size of 854 patients(425 patients in the control group and 429 patients in the intervention group).Meta-analysis revealed that extended care effectively reduced biliary tract infection(RR:0.42,95%CI:0.30-0.57),puncture wound infection(RR:0.19,95%CI:0.06-0.65),catheter protrusion or displacement in discharged patients after PTBD(RR:0.31,95%CI:0.18-0.54),catheter blockage(RR:0.23,95%CI:0.13-0.42),skin infection around the drainage tube(RR:0.30,95%CI:0.12-0.77),and catheter-related readmissions(RR:0.34,95%CI:0.18-0.65)(P<0.05).CONCLUSION Compared with conventional discharge care,extended care can effectively reduce the occurrence of complications such as biliary tract infection,puncture wound infection,catheter prolapse or displacement,catheter blockage,skin infection around the drainage tube,and catheter-related readmission in discharged patients after PTBD.

An Evidence-Based CoCoSo Framework with Double Hierarchy Linguistic Data for Viable Selection of Hydrogen Storage Methods

Hydrogen is the new age alternative energy source to combat energy demand and climate change.Storage of hydrogen is vital for a nation’s growth.Works of literature provide different methods for storing the produced hydrogen,and the rational selection of a viable method is crucial for promoting sustainability and green practices.Typically,hydrogen storage is associated with diverse sustainable and circular economy(SCE)criteria.As a result,the authors consider the situation a multi-criteria decision-making(MCDM)problem.Studies infer that previous models for hydrogen storage method(HSM)selection(i)do not consider preferences in the natural language form;(ii)weights of experts are not methodically determined;(iii)hesitation of experts during criteria weight assessment is not effectively explored;and(iv)three-stage solution of a suitable selection of HSM is unexplored.Driven by these gaps,in this paper,authors put forward a new integrated framework,which considers double hierarchy linguistic information for rating,criteria importance through inter-criteria correlation(CRITIC)for expert weight calculation,evidence-based Bayesian method for criteria weight estimation,and combined compromise solution(CoCoSo)for ranking HSMs.The applicability of the developed framework is testified by using a case example of HSM selection in India.Sensitivity and comparative analysis reveal the merits and limitations of the developed framework.

Combination of manual lymphatic drainage and Kinesio taping for treating pigmented villonodular synovitis:A case report

BACKGROUND Pigmented villonodular synovitis(PVNS)is a benign proliferative disorder that affects the synovial joints,bursae,and tendon sheaths.To date,few studies have reported on the treatment of postoperative pain and edema in patients with PVNS.Herein,we present the case of a woman who developed pain and edema in the left lower limb 1 wk after synovectomy and arthroscopic partial meniscectomy and was unable to walk due to limited flexion and extension of the left knee.CASE SUMMARY A 32-year-old woman underwent synovectomy and arthroscopic partial meniscectomy successively and was treated with a combination of manual lymphatic drainage(MLD)and kinesio taping(KT)in our hospital to alleviate postoperative pain and edema.The following parameters were assessed at 2 wk post-treatment and 1 wk post-discharge follow up:suprapatellar circumference,infrapatellar circumference,visual analog scale score,knee range of motion,pittsburgh sleep quality index score,hamilton anxiety rating scale(HAMA)score,and hamilton depression rating scale(HAMD)score.After treatment,the postoperative pain and edema in the patient’s left knee were effectively relieved,resulting in improved sleep quality and remarkably attenuated HAMA and HAMD scores.CONCLUSION Combined MLD and KT may be an effective approach for relieving postoperative pain and edema in patients with PVNS.

Bound-Preserving Discontinuous Galerkin Methods with Modified Patankar Time Integrations for Chemical Reacting Flows

In this paper,we develop bound-preserving discontinuous Galerkin(DG)methods for chemical reactive flows.There are several difficulties in constructing suitable numerical schemes.First of all,the density and internal energy are positive,and the mass fraction of each species is between 0 and 1.Second,due to the rapid reaction rate,the system may contain stiff sources,and the strong-stability-preserving explicit Runge-Kutta method may result in limited time-step sizes.To obtain physically relevant numerical approximations,we apply the bound-preserving technique to the DG methods.Though traditional positivity-preserving techniques can successfully yield positive density,internal energy,and mass fractions,they may not enforce the upper bound 1 of the mass fractions.To solve this problem,we need to(i)make sure the numerical fluxes in the equations of the mass fractions are consistent with that in the equation of the density;(ii)choose conservative time integrations,such that the summation of the mass fractions is preserved.With the above two conditions,the positive mass fractions have summation 1,and then,they are all between 0 and 1.For time discretization,we apply the modified Runge-Kutta/multi-step Patankar methods,which are explicit for the flux while implicit for the source.Such methods can handle stiff sources with relatively large time steps,preserve the positivity of the target variables,and keep the summation of the mass fractions to be 1.Finally,it is not straightforward to combine the bound-preserving DG methods and the Patankar time integrations.The positivity-preserving technique for DG methods requires positive numerical approximations at the cell interfaces,while Patankar methods can keep the positivity of the pre-selected point values of the target variables.To match the degree of freedom,we use polynomials on rectangular meshes for problems in two space dimensions.To evolve in time,we first read the polynomials at the Gaussian points.Then,suitable slope limiters can be applied to enforce the positivity of the solutions at those points,which can be preserved by the Patankar methods,leading to positive updated numerical cell averages.In addition,we use another slope limiter to get positive solutions used for the bound-preserving technique for the flux.Numerical examples are given to demonstrate the good performance of the proposed schemes.

Different timing for abdominal paracentesis catheter placement and drainage in severe acute pancreatitis complicated by intraabdominal fluid accumulation

BACKGROUND Non-surgical methods such as percutaneous drainage are crucial for the treatment of patients with severe acute pancreatitis(SAP).However,there is still an ongoing debate regarding the optimal timing for abdominal paracentesis catheter place-ment and drainage.AIM To explore the influence of different timing for abdominal paracentesis catheter placement and drainage in SAP complicated by intra-abdominal fluid accumu-lation.METHODS Using a retrospective approach,184 cases of SAP complicated by intra-abdominal fluid accumulation were enrolled and categorized into three groups based on the timing of catheter placement:group A(catheter placement within 2 d of symptom onset,n=89),group B(catheter placement between days 3 and 5 after symptom onset,n=55),and group C(catheter placement between days 6 and 7 after symptom onset,n=40).The differences in progression rate,mortality rate,and the number of cases with organ dysfunction were compared among the three groups.RESULTS The progression rate of group A was significantly lower than those in groups B and groups C(2.25%vs 21.82%and 32.50%,P<0.05).Further,the proportion of patients with at least one organ dysfunction in group A was significantly lower than those in groups B and groups C(41.57%vs 70.91%and 75.00%,P<0.05).The mortality rates in group A,group B,and group C were similar(P>0.05).At postoperative day 3,the levels of C-reactive protein(55.41±19.32 mg/L vs 82.25±20.41 mg/L and 88.65±19.14 mg/L,P<0.05),procalcitonin(1.36±0.51 ng/mL vs 3.20±0.97 ng/mL and 3.41±0.98 ng/mL,P<0.05),tumor necrosis factor-alpha(15.12±6.63 pg/L vs 22.26±9.96 pg/L and 23.39±9.12 pg/L,P<0.05),interleukin-6(332.14±90.16 ng/L vs 412.20±88.50 ng/L and 420.08±87.65ng/L,P<0.05),interleukin-8(415.54±68.43 ng/L vs 505.80±66.90 ng/L and 510.43±68.23ng/L,P<0.05)and serum amyloid A(270.06±78.49 mg/L vs 344.41±81.96 mg/L and 350.60±80.42 mg/L,P<0.05)were significantly lower in group A compared to those in groups B and group C.The length of hospital stay in group A was significantly lower than those in groups B and group C(24.50±4.16 d vs 35.54±6.62 d and 38.89±7.10 d,P<0.05).The hospitalization expenses in group A were also significantly lower than those in groups B and groups C[2.70(1.20,3.55)ten-thousand-yuan vs 5.50(2.98,7.12)ten-thousand-yuan and 6.00(3.10,8.05)ten-thousand-yuan,P<0.05).The incidence of complications in group A was markedly lower than that in group C(5.62%vs 25.00%,P<0.05),and similar to group B(P>0.05).CONCLUSION Percutaneous catheter drainage for the treatment of SAP complicated by intra-abdominal fluid accumulation is most effective when performed within 2 d of onset.

Numerical Investigations on the Resonance Errors of Multiscale Discontinuous Galerkin Methods for One-Dimensional Stationary Schrödinger Equation

In this paper,numerical experiments are carried out to investigate the impact of penalty parameters in the numerical traces on the resonance errors of high-order multiscale discontinuous Galerkin(DG)methods(Dong et al.in J Sci Comput 66:321–345,2016;Dong and Wang in J Comput Appl Math 380:1–11,2020)for a one-dimensional stationary Schrödinger equation.Previous work showed that penalty parameters were required to be positive in error analysis,but the methods with zero penalty parameters worked fine in numerical simulations on coarse meshes.In this work,by performing extensive numerical experiments,we discover that zero penalty parameters lead to resonance errors in the multiscale DG methods,and taking positive penalty parameters can effectively reduce resonance errors and make the matrix in the global linear system have better condition numbers.

Unveiling the potential of electrocautery-enhanced lumen-apposing metal stents in endoscopic ultrasound-guided biliary drainage

This editorial delves into Peng et al's article,published in the World Journal of Gastrointestinal Surgery.Peng et al's meta-analysis investigates the effectiveness of electrocautery-enhanced lumen-apposing metal stents(ECE-LAMS)in ultrasound-guided biliary drainage for alleviating malignant biliary obstruction.Examining 14 studies encompassing 620 participants,the research underscores a robust technical success rate of 96.7%,highlighting the efficacy of ECE-LAMS,particularly in challenging cases which have failed endoscopic retrograde cholangio pancreatography.A clinical success rate of 91.0% underscores its impact on symptom alleviation,while a reasonably tolerable adverse event rate of 17.5% is observed.However,the 7.3% re-intervention rate stresses the need for post-procedural monitoring.Subgroup analyses validate consistent outcomes,bolstering the applicability of ECE-LAMS.These findings advocate for the adoption of ECELAMS as an appropriate approach for biliary palliation,urging further exploration in real-world clinical contexts.They offer valuable insights for optimizing interventions targeting malignant biliary obstruction management.

Superconvergence of Direct Discontinuous Galerkin Methods:Eigen-structure Analysis Based on Fourier Approach

This paper investigates superconvergence properties of the direct discontinuous Galerkin(DDG)method with interface corrections and the symmetric DDG method for diffusion equations.We apply the Fourier analysis technique to symbolically compute eigenvalues and eigenvectors of the amplification matrices for both DDG methods with different coefficient settings in the numerical fluxes.Based on the eigen-structure analysis,we carry out error estimates of the DDG solutions,which can be decomposed into three parts:(i)dissipation errors of the physically relevant eigenvalue,which grow linearly with the time and are of order 2k for P^(k)(k=2,3)approximations;(ii)projection error from a special projection of the exact solution,which is decreasing over the time and is related to the eigenvector corresponding to the physically relevant eigenvalue;(iii)dissipative errors of non-physically relevant eigenvalues,which decay exponentially with respect to the spatial mesh sizeΔx.We observe that the errors are sensitive to the choice of the numerical flux coefficient for even degree P^(2)approximations,but are not for odd degree P^(3)approximations.Numerical experiments are provided to verify the theoretical results.